11-deoxoglycyrrhetinic acid piperazides useful as antiulcer agents

ABSTRACT

AMIDE DERIVATIVES OF 11-DEOXOGLCYRRHETINIC ACID AND ITS 3-ALKANOYL DERIVATIVES WHERE IN THE MIDE IS DERIVED FROM AMMONIA, AN ALKANOLAMINE, ADIALKANOLAMINE, AN W-HYDROXYALKYL ALKYLENE DIAMINE, AN W- BIS(HYDROXYALKYL)!ALKYLENE DIAMINE, A CYCLIC AMINE, APRIMARY OR SECONDARY ALKYLAMINE OR AN AMINO ACID ARE USEFUL AS ANTIULCER AGENTS.

United States Patent 3,814,766 ll-DEOXOGLYCYRRHETINIC ACID PIPERAZIDES USEFUL AS ANTIULCER AGENTS Hans-Jurgen E. Hess, Old Lyme, and Roger P. Nelson,

lvqvzgerford, Conn., assignors to Pfizer Inc., New York, No Drawing. Filed Nov. 3, 1971, Ser. No. 195,495 Int. Cl. C07d 51/70 US. 'Cl. 260-268 PC 8 Claims ABSTRACT OF THE DISCLOSURE Amide derivatives of ll-deoxoglycyrrhetinic acid and its 3-alkanoyl derivatives where in the amide is derived from ammonia, an alkanolamine, a dialkanolamine, an w-hydroxyalkyl alkylene diamine, an w-[bis(hydroxyalkyl)]alkylene diamine, a cyclic amine, a primary or secondary alkylamine or an amino acid are useful as antiulcer agents.

BACKGROUND OF THE INVENTION This invention relates to novel derivatives of glycyrrhetinic acid and to their use as antiulcer agents. More specifically, it relates to amide derivatives of ll-deoxoglycyrrhetinic acid and its 3-alkanoyl derivatives which are useful antiulcer agents wherein the amide is derived from ammonia, an alkanolamide; a dialkanolamine, a cyclic amine, a primary or secondary amine, an (drhy droxyalkyl alkylene diamine, an w-[bis(hydroxyalkyl)]- alkylene diamine, or an amino acid.

Chronic gastric and duodenal ulcers, collectively known as peptice ulcers, are a common affliction for which a variety of treatments have been developed. The treatment depends upon the severity of the ulcer and may range from dietary and medical (drug) treatment to surgery. A wide variety of drugs have been used to treat ulcers, the most recent of which to gain widespread attention is carbenoxolone sodium, the disodium salt of the hemisuccinate of glycyrrhetinic acid. It is reported to prevent formation of and to accelerate healing of gastric ulcers in animals, including humans (Carbenoxolone Sodium: A Sysposium, J. M. Robson and F. M. Sullivan, eds., Butterworths, London, 1968). However, its use is accompanied by undesirable aldosterone-like side effects, such as marked anti-diuretic and sodiumretaining activity, and, oftentimes, potassium loss such that continued therapy with this agent often leads to hypertension, muscle weakness and, ultimately, congestive heart failure.

Carbenoxolone sodium is almost wholly absorbed in the stomach and is not effective against duodenal ulcers except when administered as a specially fomulated capsule which enables its transport to the desired site.

A more effective treatment of peptic ulcers is therefore desirable. One which will effectively act upon ulcers in the duodenum as well as upon gastric ulcers without the need of special formulation and minimizes the aldosterone-like side effects of carbenoxolone is especially desirable.

Glycyrrhetinic acid, esters, 3-acyloxy derivatives, salts and amides thereof are known to exhibit pharmaceutical properties. British Pat. 628,443 (Aug. 14, 1963) reports glycyrrhetinic acid to be an antiniflammatory, analgesic and antipyretic agent. U.S. 3,070,623 (Dec. 25, 1962) ice describes hemi-esters of glycyrrhetinic acid, including the hemi-succinate (also known as carbenoxolone sodium), as anti-inflammatory agents. U.S. 3,070,624 (Dec. 25, 1962) teaches basic esters of the carboxy group at the 20-position of glycyrrhetinic acid which exhibit antiinfiammatory properties and inhibit the action of steroids and steroidal metabolism. Anti-inflammatory and analgesic properties are reported for amino acid salts of glycyrrhetinic acid in Japanese Pat. 32,798/69, published Oct. 27, 1965. French Pat. 215 CAM/5544M, published July 19, 1968, discloses hypoglycemic activity for glycyrrhetinic acid and its methyl ester. Salts of glycyrrhetinic acid and its hemi-esters with aluminum, zinc, bismuth and metals of Groups II-A and VIII of the Periodic Chart of the Elements are reported in Belgian Pat. 628,444, published Feb. 4, 1963, to be of value in treating digestive disorders such as gastric acidosis, inflammation and ulcers.

Amides of glycyrrhetinic acid and its 3-acyl derivatives useful as anti-inflammatory agents are described in a number of patents. Cyclic amides, e.g., the piperazine, N-acylpiperazides, N-carbalkoxypiperazides, are described in Belgian Pat. 753,773, granted July 28, 1969. The N-(lower alkyl)piperazides, piperidide and morpholide are disclosed in Japanese Pat. 26,300/67, published Dec. 13, 1967, (C.A. 69, 44067t, 1968). Additionally, simple amides, e.g., the di(lower alkyl)substituted amides, are described in this Japanese patent. US. Pat. 3,412,084 (Nov. 19, 1968) teaches alkyl, cycloalkyl, aralkyl and aryl substituted amides of glycyrrhetinic acid as well as heterocyclic amides thereof all of which are reported to be anti-inflammatory agents of low toxicity. Dialkylaminoalkyl substituted amides of glycyrrhetinic acid are described by Adanin et al., Zh. Obshch. Khim. 37, 1063- 65 (1967) (CA. 68, 2208-7q. 1968). Alkylolamine condensates of glycyrrhetinic acid useful as anti-inflammatory agents in cosmetics are reported in Japanese Pat. 8,382/67, published Nov. 4, 1967.

A variety of derivatives of glycyrrhetinic acid and ll-deoxoglycyrrhetinic acid are described by Dean et al., J. Pharm. Pharmac. 19, 682-9 (1967); including the hemi-succinates of methyl glycyrrhetinate, glycyrrhetinamide and ll-deoxoglycyrrhetinic acid; the S-acetyl derivatives of glycyrrhetinamido-orthoand para-benzoic acigs; and N (glycyrrhetinyl)glycine(glycyrrhetinuric aci Various derivatives of ll-deoxoglycyrrhetinic acids useful as intermediates are described by Ruzicka et al. in Helv. Chim. Acta 20, 1271 (1937) and 22, 197 (1939); Corey et al., J. Am. Chem. Soc. 81, 1745 (1959) and Drefahl et al., Ber. 94, 2015 (1961): the acetyl-, the methyl ester, the acetyl acid chloride, the acetyl methyl ester, the acetyl azide and the acetyl amide.

Groen et al., Acta. Med. Scand. Suppl. 312, 745-748 (1956) in a comparative study of the pharmacological activity of the adrenocortical streoids and glycyrrhetinic acid noted that in order to retain activity in either class of compounds only a limited degree of structural variation is possible. They noted that the activity seemed dependent on the presence of an ll-keto group. Vinogradov et al., Khim. v Estestn. Naukaki Sb. 40-6, 1965 (C.A. 65, 6136c, 1966) report the methyl ester of 11- deoxoglycyrrhetinic acid gave rise to a sharp increase in the excretion of water and sodium by the kidneys in dogs. 'In rats, ll-deoxoglycyrrhetinic relieved the action of deoxycorticosterone.

SUMMARY OF THE INVENTION It has now been found that ll-deoxoglycyrrhetinic acid amides of the formulae below are effective antiulcer agents:

wherein R is selected from the group consisting of hydrogen,

alkanoyl having from two to six carbon atoms, w-carboxyalkanoyl having a total of from four to five carbon atoms;

R; is selected from the group consisting of hydrogen, alkyl having from one to four carbon atoms, hydroxyalkyl having from two to four carbon atoms;

R is selected from the group consisting of hydrogen, alkyl having from one to four carbon atoms, hydroxyalkyl having from two to four carbon atoms, w-(hydroxyalkylamino) alkyl and w- [bis(hydroxyalkyl) amino] alkyl having from two to four carbon atoms in each alkyl moiety;

R and R when taken together with the nitrogen atom to which they are attached are selected from the group consisting of piperazino, N-alkylpiperazino having from one to four carbon atoms in the alkyl moiety, N-w-(hydroxyalkyl)piperazino having from two to four carbon atoms in the alkyl moiety, N-(carbalkoxy)piperazino having from one to four carbon atoms in the alkoxy moiety, pyrrolidino, piperidino and 2,6-dimethylpiperidino; with the proviso that when R is alkyl, R is alkyl or hydroxyalkyl; and when R is hydroxyalkyl R is hydroxyalkyl;

R is selected from the group consisting of hydrogen,

alkyl having from one to four carbon atoms, hydroxymethyl, l-hydroxyethyl, mercaptomethyl, Z-methylmercaptoethyl, 4-(or 5)-imidazolylmethyl, benzyl, 4'-hydroxybenzyl, 3,4-dihydroxybenzyl, 3,5-dibromo-4-hydroxybenzyl, carboxy, carbalkoxy having from one to four carbon atoms in the alkoxy moiety, w-carboxyalkyl having from one to two carbon atoms in the alkyl moiety, w-(carbalkoxy)alkyl having from one to four carbon atoms in the alkoxy group and from one to two carbon atoms in the alkyl group, w-aminoalkyl having from two to four carbon atoms in the alkyl moiety, and w-carboxamidoalkyl having from one to two carbon atoms in the alkyl moiety; 3-guanidinopropyl, 3- ureidopropyl, and 3-indolylmethyl;

R is selected from the group consisting of hydroxy, alkoxy having from one to four carbon atoms, amino and dialkylamino having from one to four carbon atoms in each alkyl moiety.

Also included in this invention are the pharmaceutically-acceptable alkali metal salts (sodium and potassium) of these compounds which contain at least one carboxy group; i.e., those wherein R is w-carboxyalkanoyl or R is hydroxy or R is carboxy or w-carboxyalkyl; and the pharmaceutically-acceptable acid addition salts of those compounds in which the amide moiety has a basic group such as those wherein R is w-(hydroxyalkylamino)alkyl-, w-[bis(hydroxyalkyl)amino]- or wherein R is w-aminoalkylor 3-guanidinopropyland those wherein NR R is piperazino, N-(w-hydroxyalkyl)piperazino or N-alkylpiperazino. Representative of the acid addition salts are the hydrochloride, hydrobromide, sulfate, phosphate, nitrate, acetate, propionate, butyrate, citrate, gluconate, tartrate, benzoate, succinate, malate, maleate and fumarate.

In addition to the alkali metal salts of those compounds of this invention containing a carboxy group, salts with metals such as the alkaline earth metals, especially calcium and magnesium, and with aluminum, zinc and bismuth and metals of Group VIII of the Periodic Chart of the Elements are also included.

DETAILED DESCRIPTION OF THE INVENTION The novel products of this invention, that is, all compounds of formulae I and II except that wherein R is acetyl and each of R and R is hydrogen, are prepared by acylation of the appropriate amine HNR R or amino acid R CH('NH )'COR reactant with an acid halide (chloride or bromide) of ll-deoxoglycyrrhetinic acid in which the S-hydroxy group is suitably protected as, for example, by acylation with a monocarboxylic acid, anhydride or acid halide, or with the acid chloride of a dicarboxylic acid half-ester. Protection of the 3-hydroxy group is necessary to permit formation of the acid halide of 11- deoxoglycyrrhetinic acid. The acid halides of the 3-acylll-deoxoglycyrrhetinic acids are prepared by treating the B-acyl-ll-deoxoglycyrrhetinic acids with excess thionyl chloride or bromide at from about room temperature to the boiling point of the thionyl halide and, subsequently, removing the excess thionyl halide. The favored acid halides are the acid chlorides since they provide satisfactory yields of desired product. The favored protecting group at the 3-hydroxy group is acetyl since it is easily removed by mild hydrolysis to regenerate the free hydroxy group.

Compounds of the above formulae wherein R is wcarboxyalkanoyl group, e.'g., an alkyl ester, and preferably a methyl or are hydrolyzed, by means of lithium iodide in N,N-dirnethylformamide at the reflux temperature. This treatment, of course, also hydrolyzes any ester group present in the amide moiety. Alternatively, an 0:- carbobenzyloxyalkanoyl derivative can be used in place of an w-carbalkoxyalkanoyl derivative. The benzyl group is easily removed by catalytic hydrogenation, e.g., with palladium on charcoal. This procedure has the advantage of permitting retention of alkyl ester groups in the amide moiety.

The 3-acyl-1l-deoxoglycyrrhetinic acid amides thus produced, in addition to being anti-inflammatory and antiulcer agents, serve as intermediates, particularly for the production of half esters with dicarboxylic acids. The 3- hydroxy group produced on hydrolysis is reacylated with a different acid (e.g., acid anhydride or halide), especially 6 with a dicarboxylic acid, to produce a half-ester of the a favored excipient for oral use. Compositions containdicarboxylic acid, e.g., a hemisuccinate. ing from about 50% to about 90% by weight of poly- When the amide moiety (formulae I and II) contains vinylpyrrolidone or Carbowax 6000 are especially elfecan amino, hydroxy or mercapto group, such group must tive for oral administration. Higher or lower amounts of excipient can, of course, be used but appear to offer no first be protected before acylation of the 3-hydroxy group.

advantages over these proportions. For intraperitoneal A suitable and convenient protecting group is the benzyl group since it is easily removed by hydrogenolysis. This use, the polyvinylpyrrolidone formulations are suspended group can be present in the HNR R or R CH(NH )COR in carriers such as water or in saline solution containing reactant or be introduced into the 3-acyl-1 l-deoxoglycyr- 1% carboxymethylcellulose and 0.1% Tween 80 (polyrhetinic acid amide. oxyethylene ethers of partial esters of fatty acids and The compounds described he in r fl ti nti l e hexitol anhydrides derived from sorbitol, available from agents via the intraperitoneal and oral routes of adminis- Atlas Chemical Industries, The Water Soluble P tration against gastric d duoden l l Th ducts of this invention are conveniently administered in ucts not only accelerate healing of such ulcers but also Water Solution. prevent formation of ulcers and decrease gastric acid The effectiveness f the P d cts of t is invention aS output in animals, including humans. They can, thereantiulcer agents is determined by the stressed rat assay fore, be said to be useful for the control of gastric and as S- duodenal ulcers The incidence of side effects, e g,, 3L Cold-restraint stressed rat: Non-fasted female rats dosterone-like fluid retention and electrolyte disturbances, (Charles River Strain) Weighing 70-140 are attendant with the us of ny f th compounds f thi administered the drug or carrier (control animals) intrainvention is relatively low and is nonexistent with some Peritoneally Saline Solution containing 1% Y of them. Particularly valuable in this respect are 1-(35- methyleellnlose and 01% Tween 0f Orally Water) acetoxy-ll-deoxo-l8fi-olean-l2-en-30-oyl) 4 (2 hythree hours before being lightly anesthetized with ether droxyethyl)piperazine; N-(2-hydroxyethyl)-3fi-hydroxyand taped in the supine position to individual sheets of 1l-deoxo-lsp-olean-12-en-30-ca box mid d N [3- Plexiglass. After recovery from the anesthesia, the re- [bis-(2 hydroxyethyl)amino]propyl] -3fi-acetoxy-11-destrained animals are positioned horizontally in a refrigeraoxo-1sp-olean-12-en-30-e bo amid tor maintained at 1012 C. and three hours later sac- The valuable products of this invention can b d ini rificed by cervical dislocation. The abdomen of each rat tered alone or in combination with a pharmaceutical is opened, the pylorus clamped, the stomach inflated with carrier selected on the basis of the chosen route of ada e Via an Oral tube, the esophagus clamped and the ministration and standard pharmaceutical practices. For Stomach excised. The stomachs are placed in a 0.4% example, they can be administeredorally in the form of formaldehyde solution for approximately 30 seconds to tablets containing such excipients as polyvinylpyrrolidone, harden the outer layers and facilitate examination. Each a Carbowax (non-volatile, solid polyethylene glycols stomach is then cut open along the greater curvature and available from Carbide and Carbon Chemicals Corporat e g lar portion (hind stomach) examined for damtion), especially Carbowax 6000, starch, milk sugar, etc. age. The number of gastric erosions, their severity and the or in capsules alone or in admixture with the same or l r f t st ma hs is recorded. The Mann-Whitneyequivalent excipients. They may also be administered WilcoXon rank sum test is used to compare the median orally in the form of elixirs or oral suspensions which number of gastric erOSiOnS in the Control gT np With the may contain flavoring or coloring agents or be injected median number of gastric erosions in each drug-treated parenterally; that is, for example, intramuscularly or subgroups to determine if they are statistically different. cutaneously. For parenteral administration, they are best n et a Introduction to Statistical y 3rd used in the form of a sterile solution which may be either ed, M G BOOK p y, New York, pp. 344- aqueous such as water, isotonic saline, isotonic dextrose, 347, 1969.)

Ringers solution, or non-aqueous such as fatty oils of Results thus obtained with carbenoxolone (Drug A) vegetable origin (cotton seed, peanut oil, corn, sesame) and 1-(3 3-acetoxy-18/3-olean-12-en-30-oyl) 4 (2 hyand other non-aqueous vehicles which will not interfere droxyethyl)piperazine hydrochloride (Drug B) are prewith the therapeutic efiiciency of the preparation and are sented below.

TABLE I.-ANTIU'LCER ACTIVITY IN STRESSED RAT ASSAY Drug 1 Carrier 9 30 4O 80 160 320 640 No. 5... Yes--. N

..... No.. No Yes-.- Yes. No

l PVP =polyvinylpyrrolidone. 2 Saline=saline solution containing 1% carboxymethylcellulose and 0.1% Tween 80. 3 P.o.=ora1; i.p.=intraperitoneal.

non-toxic in the volume or proportion used (glycerol, A significant reduction in gastric glandular mucosal propylene glycol, sorbitol). Additionally, compositions lesions at 80 and 160 mg./kg. is obtained with Drug B- suitable for extemporaneous preparation of solutions prior PVP formulations via the oral route. Unformulated Drug to administration may advantageously be made. Such B is comparable to carbenoxolone via the intraperitoneal compositions may include liquid diluents, for example, route.

propylene glycol, diethyl carbonate, glycerol, sorbitol, The effect of the products of this invention on renal etc.; buffering agents as well as local anesthetics and excretion of water and electrolytes in rats is determined inorganic salts to afford desirable pharmacological in the following manner:

properties. Rat diuretic assay: The water load (25 mL/kg.) or For both oral and intraperitoneal administration, a 7 water load-containing drug is administered orally to each dosage range of from about 150 mg. to about 300. mg. of three groups of two rats. Urine is collected for 5 hours per day is effective. The dosage level can, with careful and the samples from each group are analyzed by standsupervision, range up to as high as about two grams per ard flame photometric techniques for sodium and potasday. Propylene glycol is a suitable and convenient carsium content. Urinary volume (ml./kg./5 hr.), sodium rier or diluent for intraperitoneal use. Carbowax 6000 is excreted (meq./kg./5 hr.), potassium excreted (meq./

Effect of carbenoxolone and PVP formulated Drug B on the renal excretion of water and electrolytes and the Na/K ratio in the rat 50% Drug 18-50% PVP Carbenformuoxolone lation Volume (ml./kg./5 hrs.) i J, [1 Na. (meq./kg.l5 hrs.) i [1} K (meq./kg./5 hrs.). [T1 1 E [Na] hilillilll ll 1 [K] (meqJL) T l T i 1 N effect.

The number of arrows indicate the magnitude of the effect; brackets indicate a non-significant effect.

In water loaded rats, with increasing dose, carbenoxolone causes a moderate decrease in urinary volume and sodium, a marked decrease in the sodium/potassium ratio and a marked increase in potassium concentration, a slight but non-signi ficant increase in urinary potassium and a decrease in urinary sodium concentration. In contrast, formulated Drug B caused a moderate increase in uninary sodium concentration, a slight increase in potassium concentration, and a slight but non-significant increase in both urinary sodium and potassium and a decrease in urinary volume. It had no effect on the sodium/potassium ratio. The rate of increase in urinary potassium concentration with increasing doses of carbenoxolone is significantly greater than with formulated Drug B. The rate of decrease in urinary volume with dose is significantly greater with carbenoxolone than with formulated Drug B Their effect on gastric acid output in pylor-us-ligated (i.e. Shay) rats is determined by the following procedure.

Shay rat: Forty-eight hours before surgery female rats (Charles River C-D strain; 100-140 gms.) are individually caged and taken off normal food. Each animal is given two sugar cubes and water ad libitum to effect emptying of the stomach. Drug or carrier is administered intraperitoneally and three hours later, under ether anesthesia, the abdomen is shaved and opened along the linea alba. After exposing and ligating the pylorus, the incision is closed and the animal is returned to its cage and allowed to regain consciousness. Three hours later the animal is sacrificed by cervical dislocation, the abdomen reopened, the distal esophagus clamped, and the stomach excised. The stomach is cut open and the contents washed into a beaker with one ml. of deionized water. The volume of gastric juice is recorded following centrifugation. =Excessively dirty (greater than 0.5 ml. of solids) or bloody samples are discarded. The acidity of one ml. of gastric juice is determined by titration with a standardized NaOH (0.1 N) solution using phenolphthalein as an indicator and total acid output (,ueq. H+/ 100 gms. body weight/ 3 hours) is calculated. A non-paired t test is used to compare the means of the control and tested groups. (Dixon et al., Technometrics, X, 83-98, 1968). Carbenoxolone and Drug B at 40 mg./kg. body weight consistently reduced gastric acid output in the three hour Shay rat. At 80 mg./l g., carbenoxolone, in contrast to Drug B, significantly decreased acid output in the Shay rat. 'N-[2-(2-hydroxyethylamino) 3/3-acetoxy-18,8-olean-12-en-30-carboxamide and N-(3fl-acetoxy-l8fl-olean 12 en-30-oyl)-L-histidine, methyl ester exhibit no effect upon acid output in the Shay rat.

8 EXAMPLE I N- Z-hydroxyethyl) -3' 8-hydroxy-1 8 B-ole an- 1 2-en-3 0- carboxamide (A) 3B-hydroxy-18,8-olean-12-en-30-oic acid: Eighty grams (0.169 M) of 1 8B-glycyrrhetinic acid in 1500 ml. of glacial acetic acid is hydrogenated at 50 C. using 20 g. of platinum oxide. The reaction is allowed to proceed for 3 hours at a pressure of 350 p.s.i. Additional solvent is added to the reaction in an attempt to dissolve some of the product which precipitates. The catalyst is filtered and thoroughly washed with chloroform. Concentration of the combined filtrates followed by recrystallization of the solid residue from acetic acid gives 35.4 g., 46.6% of the title product; M.P. '319321 C. Ruzicka et al., Helv. Chim. Acta 20, 1271 (1937) report M.P. 330 C.

(B) 3B-acetoxy-18B-olean-12-en-30oic acid: To a solution of 53.8 g. (0.120 M) of 3,8-hydroxy-18B-olean-12-en- 30-oic acid in 615 ml. of pyridine is added 615ml. of acetic anhydride. The reaction is refluxed for one hour, cooled and stirred at room temperature for twenty-three hours. It is acidified with 10% hydrochloric acid and the resulting precipitate filtered and dissolved in chloroform. The chloroform solution is washed with water, dried over sodium sulfate and treated with activated charcoal. Concentration of the solution gives a solid which is recrystallized from methanol-chloroform to give 50.8 g., of the acetoxy derivative; M.P. 300302 C. Corey et al., I. Am. Chem. Soc., 81, 1745 (1959) report M.P. 305- 307 C.

(C) 3fi-acetoxy-l8fl-olean 12 en-30-oyl chloride: A solution of 42.0 g. (0.0843 M) of 3B-acetoxy-l8fl-0lean- 12-en-30-oic acid in 400 ml. of thionyl chloride is stirred at 50 C. for one hour. The excess thionyl chloride is removed under reduced pressure and the residue recrystallized from methylene chloride-hexane to give 37.9 g., 87% of the desired acid chloride; M.P. 245.5 -247.5 C. Ruzic ka et al., Helv. Chim. Acta 22, 195 (1939) report M.P. 24825 1 C. e

(D) N- (2 hydroxyethyl)-3B-acetoxy-l8fi-olean-12-en- 30-carboxamide: A solution of 10.45 g. (0.0202 M) of 3 8-acetoxy-18,8-olean-12-en-30-oyl chloride in 75 ml. of methylene chloride is added dropwise with stirring to a solution of 126 ml. (2.02 M) of 2-aminoethanol in 55 ml. of methylene chloride. 7

The reaction is stirred at room temperature for 17 hours and then washed successively with 10% hydrochloric acid, sodium bicarbonate solution and water. The organic layer is dried over sodium sulfate and concentrated to dryness to give 10.8 g., 98.5% of the intermediate acetate; M.P. 239-240 C.

(E) Hydrolysis of intermediate acetate: A solution of 10.28 g. (0.0188 M) of acetate in m1. of methanol and 535 ml. of 10% KOH/MeOH is stirred at room temperature for eighteen hours and then concentrated to dryness, acidified with 10% hydrochloric acid and extracted with methylene chloride. The combined organic extracts are dried over sodium sulfate and concentrated to dryness. Recrystallization of the residue yields 7.54 g., 80.3% of the title amide product; M.P. 245 247 C.

EXAMPLE II 1-(3y3-acetoxy-l8B-olean-12-en-30-oyl)-4-(2- hydroxyethyl) piperazine To a solution of 5.20 g. (0.0386 M) of piperazine ethanol in 100 ml. of methylene chloride is added dropwise with stirring 10.0 g. (0.0193 M) of acid chloride (Example 1-0). A precipitate forms approximately five minutes after the acid chloride is added. The reaction mixture is stirred at room temperature for 15 hours and then made basic with 50% sodium hydroxide. The basic mixture is extracted with methylene chloride and the combined organic extracts washed with water, dried over sodium sulfate and treated with activated charcoal. Re-

moval of the solvent and recrystallization of the residue from acetone alfords 9.15 g., 77.6% of the title product; M.P. 234235 C.

The hydrochloride salt is prepared by bubbling hydrogen chloride gas into a solution of the title product in chloroform at 15 C. The salt is precipitated by addition of ether, and then filtered and dried. It is recrystallized from chloroform-ether; M.P. 320323 C.

EXAMPLE II'I N-[3- [bis-(2-hydroxyethyl)amino] propyl]-3B-acetdxy- 18fi-olean-l2-en-30-carboxamide A solution of 7.7 g. (0.048 M) of N-(3-aminopropyl) diethanolamine in 50 ml. of methylene chloride is treated dropwise with 10.0 g. (0.019 M) of 3fi-acetoxy-18B-olean- 12-en-30-oyl chloride in 50 ml. of methylene chloride. The reaction is stirred at room temperature for 3 hours and then made basic with 50% sodium hydroxide. The mixture is extracted with methylene chloride and the combined organic extracts washed with Water, dried over sodium sulfate, and treated with activated charcoal. The solvent is removed and the residue triturated with ether to give a solid which is recrystallized from acetone yielding 7.8 g., 65% of product; M.P. 192-194 C.

The hydrochloride salt is prepared according to the procedure of Example II but using methylene chloride in place of chloroform as solvent; M.P. 282283 C.

The title compound is hydrolyzed to its 3p-hydroxy derivative by the procedure of Example V-B.

EXAMPLE IV N-[3-(Z-hydroxyetthylamino)propyl]3J8-acetoxy-18 8- olean-12-en-30-carboxamide To a solution of 3.77 g. (0.032 M) of 1,3-diamine-N- fl-hydroxyethyl) propane in 50 ml, of methylene chloride is added dropwise with stirring 7.0 g. (0.013 M) of the acid chloride of Example LC in 75 ml. of methylene chloride. The reaction mixture is stirred at room temperature for hours and made basic with 50% sodium hydroxide. The methylene chloride layer is removed, washed with water and dried over sodium sulfate. Removal of the solvent and trituration of the residue with ether gives the product as a solid. Recrystallization of the solid from acetone aifords 6.15 g., 79.1% of product; M.P. 188- 189 C.

EXAMPLE V 1-(3p-hydroxy-18,3-olean-12-en-30-oyl)-4- methylpiperazine hydrochloride (A) 1-(3fi-acetoxy)-l818 olean 12 en -oyl)-4- methylpiperazine: To a solution of 10.5 g. (0.0202 M) of 3fi-acetoxy-11-deoxo-18fi-olean-12-en 30-oyl chloride in 100 ml. of methylene chloride is added 4.1 g. (0.040 M) of l-methylpiperazine. The reaction mixture is stirred at room temperature for 19 hours and then washed successively with dilute hydrochloric acid, aqueous sodium bicarbonate and water. The organic layer is separated, dried over sodium sulfate and concentrated to give 10.9 g., 93.7% of the acetate; M.P. 198-200 C.

(B) Hydrolysis of the acetate: The acetate 8.0 g. (0.014 M) is stirred in 528 ml. of 10% KOH/MeOH at room temperature for hours. The reaction is then concentrated to dryness, acidified With 10% hydrochloric acid and extracted with methylene chloride. The combined organic extracts are dried over sodium sulfate, concentrated to dryness and the resulting solid recrystallized from methanol yielding 5.2 g., 65.8% of the title piperazide; M.P. 324325 C.

10 EXAMPLE vr N- [2- (Z-hydroxyethylamino ethyl] -3 B-acetoxy- 1 8,9- olean-12-en-3 O-carboxamide To a solution of hydroxyethylethylenediamine 2.6 g. (0.025 M) in 50 ml. of methylene chloride is added 5.0 g. (0.01 M) of 3fi-acetoxy-18,8-olean-12-en-30-oyl chloride (Example I-C) in 50 ml. of methylene chloride over a period of 15 minutes. The reaction is stirred at room temperature for 4 hours and then made basic with 25% sodium hydroxide solution. The organic layer is separated,'

EXAMPLE VII (A) The Sfl-acyLgIycyrrhetinic acid amides listed below are prepared from the appropriate amine HNR R and the appropriate 3B-acyl-1l-deoxoglycyrrhetinic acid chlorides of Example I-C and Preparation A (R =hydrogen and R by the procedure of Example VI.

TABLE-Contlnued R1 R2 R8 om cm) 400 H OHaCHzOH CH1 CH2) 4C0 CHzCHzOH CHzCHzOH CHa(CHz)4CO H EM CHaECHzhCO (CH2)4OH (CH2)4OH CH2 CH2) 4C0 CH: CHzCH2OH H (CH2) 2NH(CH2)3OH CHaCO H (CH2)aNH(CHz)4OH CHaCO H (CH2)2N((CH2)4OH)1 CHaCO H (CH2)4N(CHzCH2OH):I CHaCO H (CH2) 4NH(CH:) 40H CH CHQCO H (CH2) aNH(CHaCH2OH) CHzCHzCO H (CH9) 4N (CHzCHzOEDz CH:(CH2)2CO H (CH2)aN(CH2CH2CH2OH)2 CH1 (CH2) 400 H (CH1) gNH (CHz)4OH CHICO CHnCHzNHCHnCH: CHICO CHaCHzN(C2Hs) CHzCHa CH CO CH2CH2N(l1-C4Ho) CHzCHs CHsCO CH2CH2N[(CH2) 4OH]CH2CH2 CH CO CH2CH2N(COOCH3) CHZCH? CHsCO CHzCHzN(COO-n-C;H CHzCHi CHaCO CHzCHzCHzCHz CHICO CHaCHaCHzCHzCH: CHaCO CH(CH;) CH2CH2CH2CH(CHI) CHQCHQCO CHaCHaNHCHnCH: CHrCHzCO CH2CHaN(CH CHzCH: CHZOHZCO CHzCHzN (CHzCHzOH) CHiCH: CHgCHzCO CH2CHaN(COO CHI) CHaCHl CHsCHgCO CHzCHlCHzCH: CHgCHgCO CH2CH2CHCH2CH2 CHgCHaCO CH(CH;) CH2CHzCH2CH(CHl) CH: (CH2):CO CH2CH:N(CH3) OHzCHz CH;(CH2)2CO CH2CH2N(CH2CH2OH) CHgCHi CHa(CH2) 2C0 CHzCHzCHzCHz CHa(CH2)nCO CH2CHzCH2CH2CH2 CH (CH2)':CO CHzCHaNHCHzCHz CH;(CH2)|CO CH2CH2N(l-O H7) CHzCHa CH;(CH2)1CO CH2CHaN(CH2CH2CH2OH) CHzCHa CH:(CH2)3CO CHzCHzN(COOCzH5) CHaCHa CH;(CH2) 4C0 CH2CHIN(l1-C3H1) CHzCHz CH (C Hz) 00 CHzCHzN(COO-n-C4Ho) CHzCH: CH (CH2)4C0 CHzCHzCHzCHz CHaCO H CH(C2H5) CHQOH CHsCO H CH(CH:)CH(0H) CH3 CHaCO H CHzCHzO 01H! CHzCO H (CHz) O C1H1 CH|CO H (CH2)4O C1H1 CHsCO CH2CH2O (31H! CHzCHzO 01111 (311300 CH2CH(0 C7H1) CH1 CH2CH(O C1H1) CH CH CO CH: CH2CH2O C1H1 CHaCO C 110 CHzCHzO C7H1 CHaCHzCO H CHzCHzO C H CHrCHzCO (CH2)3OC7H1 (CH2)3OC7H1 CH (CH2)2CO H CHzCHzO C1H1 CHz(GH2)1CO 02H (CH2) OC1H1 CHa(CH2)aCO H (CHzhO C H1 CHa(CH2)4CO (CH2) 4O C1H1 (CH2) 4O C1H1 (B) Hydrolysis of the 3-acyloxy groups of the above compounds according to the procedure of Example V-B provides the corresponding 3-hydroxy derivatives.

EXAMPLE VIII Hemisuccinate of N-(2-hydroxyethyl)-3;9-hydroxy- 18/3-olean-12-en-30-carboxamide (A) 3 3 (fi-carbomethoxypropionyloxy) 18;3-oleanl2-en-30-oic acid: A solution of ll-deoxoglycyrrhetinic acid (5.0 g.) in pyridine (20 ml.) is treated with a solution of .B-carbomethoxypropionyl chloride (3 ml.) in pyridine (50 ml.). The reaction mixture is allowed to stand for four days and then poured into water (100 ml.). The product is extracted with ether (3X 250 ml.), the combined ethereal extracts dried (MgSO and evaporated under reduced pressure. The residue is recrystallized from methanol-water.

Similarly, the corresponding 3,8- (y-carbomethoxybutyryloxy)-derivative is prepared substituting 'y-carbomethoxybutyrylchloride for ,8 carbomethoxypropionyl chloride.

(B) A solution of 313-(fl-car-bomethoxypropionyloxy)- 18/8-olean-12-en-30-oyl chloride (11.54 g., 0.02 M, prepared from the precursor acid by the procedure of Example I-C) in methylene chloride (75 ml.) is added dropwise with stirring to a solution of 2-aminoethanol (2.0 M) in methylene chloride (50 ml.) and the mixture stirred at room temperature for 17 hours. It is then washed successively with 10% hydrochloric acid, sodium bicarbonate solution and water and then dried (Na SO The product is recovered by removal of the solvent under reduced pressure.

(C) Hydrolysis of the ester is accomplished by treating a solution of the ester in N,N-dimethylformamide 12 ml./1.0 mM. of ester) with lithium iodide (1.0 g./1.0 mM. of ester) under reflux for 12 hours. The reaction mixture is cooled, poured into water and the product recovered by filtration if solid or by extraction with methylene chloride.

In this manner, the hemisuccinate and hemiglutarate esters of the amides of Examples I-VII are prepared by substituting the appropriate 3 fi-carbomethoxyalkanoyloxy- 11 deoxyglycyrrhetinic acid chloride for the 35 alkanoyloxy-1l-deoxo-glycyrrhetinic acid chloride of the examples.

EXAMPLE IX N-(3B-acetoxy-18p-olean-12-en-3 0-0y1)L-histidine methyl ester A solution of 15.0 g. (0.0291 M) of BB-acetoxy-ISB- olean-12-en-30-oy1 chloride in 75 ml. of methylene chloride is added dropwise to a hazy solution of 7.04 g. (0.0291 M) of L-histidine methyl ester dihydrochloride and 11.3 g. (0.0872 M) of N,N-diisopropylethylamine in ml. of methylene chloride. The reaction mixture is stirred at room temperature for five days and then washed with Water, treated with activated charcoal and dried over magnesium sulfate. Concentration of the solution leaves an oily solid which is crystallized with hot methanol and, subsequently, recrystallized from chloroform-methanol to give 5.6 g. of unidentified by-product; M.P. 262-263 C., and impure product. The impure product is recrystallized from chloroform-methanol yielding 11.57 g., 61.5% of the title product; MP. 207 20 9 C.

EXAMPLE X Repetition of the procedure of Example IX but using the appropriate amino acid in place of L-histidine methyl ester dihydrochloride and the appropriate 3B-acyl-11-de oxoglycyrrhetinic acid chlorides affords the following compounds. Suflicient N,N-diisopropylethylamine is used in a given reaction to neutralize the acid (HCl) byproduct plus any acid introduced with the amino acid reactant.

R1 Ra Ra CHzCO H O CHI CHzCO CH! O 02H; CHsCO CIHB O CH; CH|CO CH2CH(CH:)2 NH: @5 00 CHzOH O-(n-CHp) CHaCO CH(OH)CH; OCH; OHzCO CHM-(or 5)-Im l OCH: CHgCO CoHs-CH: O CzHi CHzCO 4-HO CsHCHn O CH; CHaCO C000: 5 0021515 CHsCO COO-nCzH1 O-(n-C H1) CHaCO CHaCOOH OCH! CHaCO CHzCOOH NH: CHaCO CHzCHzCOOH OCaHa CHICO CHzCHzNHz O CH: CHsCO (CH2)|NH2 O CHI CHICO CHzCHzCONH: OCH! CHzCO CHzCONH: OCa I CHaCO (CH2):NHC (=NH)NH: NHI: CHaCO (CH MNHCONH: OCH] CHaCO CHz.(3-lndolyl) OCH: CHflCO CH; N(CH$)1 CHzCO H N(n-C;H1)z CH3CO CHHOH N(C:H5) 3 CHaCO CoHsCH: NH:

1 Im=imidazolyL Hydrolysis of the above products as described in Example V-B affords the corresponding derivatives wherein R is H, and all ester and amide values of R and R are converted to carboxy.

EXAMPLE XI Hemisuccinate of 1-(3,8-hydroxy-18B-olean-12-en-30- oyl -4-methylpiperazine The product of Example V (0.01 M) is dissolved in dry pyridine (30 ml.) and a solution of succinic anhydride (0.012 M) in dry pyridine ml.) added, followed by dry triethylamine (5 ml.). The mixture is heated on a boiling water bath for ten hours and then poured into excess dilute hydrochloric acid and ice. The product is filtered off and Washed with water. It is then dissolved in chloroform, the solution repeatedly extracted with dilute hydrochloric acid followed by water. The chloroform solution is then dried (Na SO and evaporated to give the product.

In like manner, the hemiglutarate is prepared substituting glutaric anhydride for succinic anhydride.

Repetition of this procedure but using the products of Example VII which contain no hydroxyalkyl group in the amide moiety affords the hemisuccinates and hemiglutarates of the compounds.

EXAMPLE XII N- [3 fi-(18-carbomethoxypropionyloxy)-18/3-olean- 12-en-30-oyl]serine, methyl ester A solution of 3B-(fl-carbomethoxypropionyloxy)48/3- olean-12-en-30-oyl chloride (11.54 g., 0.02 M), methyl ester of the hemisuccinate of ll-deoxoglycyrrhetinic acid chloride, in methylene chloride (75 ml.) is added dropwise to a solution of serine methyl ester (2.38 g., 0.02 M) and N,N-diisopropylethylamine (2.58 g., 0.02 M) in methylene chloride (150 ml.). The reaction mixture is stirred for five days at room temperature and then washed with water, decolorized with activated charcoal and dried over magnesium sulfate. Concentration of the solution affords the product.

Repetition of this procedure but using 3fi-(y-carbomethoxybutyryloxy)-l8fi-olean-12-en-30-oyl chloride as the O-acylating agent provides N-[Elfl-(y-carbomethoxybutyryloxy)-18/8-olean-l2-en 30-oyl)serine, methyl ester.

EXAMPLE XIII N- [3 8- (p-carboxypropionyl) -1 8fi-olean-12-en-30- oyl] serine The title dimethyl ester product of Example XII (0.659 g., 1 mM.) in N,N-dimethylformamide (75 ml.) is treated with anhydrous lithium iodide 10 g.) and the solution heated at reflux for 12 hours. The reaction mixture is cooled, poured into water and the product recovered by filtration or by extraction with methylene chloride.

Similarly, the remaining diester of Example XII is hydrolyzed to the corresponding product N-[3 8-(y-carboxybutyryloxy)-18fi-olean-12-en-30-oyl] serine.

EXAMPLE XIV N- [3 3-(fi-carb0xypropionyloxy)-18fl-olean-12-en- 30-oyl] lysine The procedure of Example XII is repeated but using the e-carbobenzoxy derivative of lysine methyl ester in place of serine methyl ester. The product thus obtained is taken up in ethanol and treated with hydrogen in the presence of 5% palladium on charcoal to remove the protective carbobenzoxy group. Filtration of the catalyst followed by removal of the solvent gives the methyl ester of the hemisuccinate.

Hydrolysis of the dimethyl ester according to the procedure of Example VIII-C, using, of course, twice the proportion of lithium iodide produces the title product.

EXAMPLE XV N- [3 ,8- ,B-carboxypropionyloxy) 1 8 fi-oleanl 2-en-30- oyl] aspartic acid, methyl ester Following the procedure of Example VIII-A, but using fl-carbobenzoxy propionyl chloride produces 3 3-( 8-carbobenzoxy propionyloxy)-18fi-olean-12-en-30-oic acid. The acid chloride is then prepared by the procedure of Example I-C.

Methyl ,B-amino-B-carbobenzoxy propionate,

is then treated with the above-produced acid chloride by the procedure of Example XII to give the benzyl ester of the title product.

The benzyl group is removed using hydrogen, 5% palladium on carbon in ethanol according to Example XIV to give the title product.

Repetition of this procedure but using methyl 'y-amino 'y-carbobenzoxybutyrate in place of methyl fl-amino-B- carbobenzoxy butyrate produces the corresponding 3,3-( carboxybutyryloxy) derivative.

EXAMPLE XVI N-[3,3-(fl-carboxypropionyloxy)-18fi-olean-12-en- 30-oyl] cysteine EXAMPLE XVII N-[3 3-(,3-carboxypropionyloxy)-18 3-olean-12-en- 30-oyl] arginine This product is prepared from nitro arginine methyl ester hydrochloride and the methyl ester of the hemisuccinate of ll-deoxoglycyrrhetinic acid chloride by the procedure of Example XII. The N-[SB-(fi-carbomethoxypropionyloxy)-l8l8-olean-12-en 30 oyl] nitroarginine, methyl ester thus produced is converted to the corresponding arginine methyl ester by reaction with hydrogen and Pd/ C as described in Example XIV.

Hydrolysis of the dimethyl ester with lithium iodide according to the procedure of Example XIII affords the title product.

, In like manner, the hemiglutarate of the title product is prepared using the methyl ester of the hemiglutarate of ll-deoxoglycyrrhetinic acid chloride.

EXAMPLE XVIII Following the procedure of Examples VIII and XI- XVI, the compounds listed below are prepared from appropriate reactants.

OHR4O (Lain-LR, I

1 6 EXAMPLE XIX Acid addition salt formation The appropriate 1l-deoxoglycyrrhetinamide of formulae I or II which contains a basic group is dissolved in a suitable solvent, e.g., chloroform, methylene chloride, ethanol, and an excess of the appropriate acid added to the solution. The product, if insoluble in the solvent, is recovered by filtration. The product, if soluble in the solvent, is recovered by addition of a non-solvent for the salt, e.g., ether, or by evaporation of the solvent under reduced pressure.

In this manner, the hydrochloride, hydrobromide, tartrate, citrate, acetate, propionate, butyrate, gluconate, benzoate, succinate, malate, maleate, fumarate, nitrate, sulfate, and oxalate salts of the products of Examples II-XVIII which contain a basic group are prepared.

EXAMPLE XX PREPARATION A BB-acyloxy-l8/3-olean-12-en-30-oic acids (via acid anhydride) The procedure of Example I-B is repeated but using the appropriate acid anhydride in place of acetic anhydride to give the following 3B-acyl derivatives of ll-deoxoglycyrrhetinic acid:

propionyl butyryl isobutyryl valeryl caproyl PREPARATION B 3f3-acyloxy-l8fl-olean-12-en-30-oic acids (via acid chloride) A mixture of ll-deoxoglycyrrhetinic acid (0.1 mM.), the appropriate acyl chloride (10 mM.) and pyridine (10 mM.) is heated on a water bath for 1.5 hours and then poured into water. The aqueous mixture is extracted with ether and the ether solution washed successively with dilute aqueous sodium hydroxide and hydrochloric acid and then dried (Na SO Evaporation of the solvent affords the product which is recrystallized from a suitable solvent such as methanol-chloroform.

The following 3fi-acyl derivatives are thus prepared:

acetyl propionyl caproyl PREPARATION C 3p-acyloxy-l8p-olean-l2-en-30 oyl chlorides The 3,3-acyl derivatives of Preparations A and B derived from monocarboxylic acids are converted to their acid chlorides by the procedure of Example I-C.

PREPARATION D 3 p- 'y-c arbomethoxybutyryloxy) -18 8-olean-12-en-3 O-oyl chloride To a solution of ll-deoxoglycyrrhetinic acid (4.86 g.) in pyridine (20 ml.) is added 'y-carbomethoxybutyryl chloride (3 ml.) in pyridine (50 ml.). The reaction mix wherein R is selected from the group consisting of hydrogen, alkanoyl having from two to six carbon atoms, w-carboxyalkanoyl having a total of from four to five carbon atoms;

R is selected from the group consisting of hydrogen, alkyl having from one to four carbon atoms, hydroxyalkyl having from two to four carbon atoms;

R and R when taken together with the nitrogen atom to which they are attached are selected from the group consisting of piperazino, N'-alkylpiperazino having from one to four carbon atoms in the alkyl moiety, N-w- (hydroxyalkyl)piperazino having from two to four carbon atoms in the alkyl moiety, N-(carbalkoxy)piperazino having from one to four carbon atoms in the alkoxy moiety; and

the pharmaceutically-acceptable alkali metal salts of those compounds having at least one carboxy group; and

the pharmaceutically-acceptable acid addition salts of those compounds having a basic group.

2. An ll-deoxoglycyrrhetinic acid derivative according to claim 1, formula I.

3. A compound according to claim 2 wherein R, is hydrogen and NR R is N-(w-hydroxyalkyl)piperazlno.

4. A compound according to claim 2 wherein R is alkanoyl, and NR R is N-(w-hydroxyalkyl)piperazino.

5. A compound according to claim 2 wherein R is w-carboxyalkanoyl and NR R is 4-(w-hydroxyalkyl) piperazino.

6. 1-(3 3-hydroxy-18fi-olean-12-en-30-oyl)-4-(2-hydroxyethyl)piperazine, a compound according to claim 3 wherein NR R is 4-(2-hydroxyethyl)piperazino.

7. 1-(SB-acetoxy-l8fl-olean-12-en-30-oyl)-4-(2-hydroxyethyl)piperazine, a compound according to claim 4 wherein R is acetyl and -NR 'R is 4-(2-hydroxyethyl) piperazino.

8. 1-(3fi-carboxypropionyloxy-18fl-olean-12-en-30-oyD- 4-(2-hydroxyethy1)piperazine, a compound according to claim 5 wherein R is carboxypropionyloxy and NRgRg' is 4-(2-hydroxyethyl)piperazino.

References Cited UNITED STATES PATENTS 3,412,084 11/1968 Turner et a1. 260-268 PC 3,523,942 8/1970 Holden 260-268 PC OTHER REFERENCES Turner et al., Chem. Abstr., vol. 74, 001. 1002430 (1971), abstracting German 2,034,694.

Turner et al., Chem. Abstr., vol. 73, col. 131170k (1970), abstrating German 2,001,906.

Turner, Chem. Abstr. vol. 74, col. 8817521 (1971), abstracting German 2,027,577.

DONALD G. DAUS, Primary Examiner US. Cl. X.R.

T31533 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIUN lnventofls) Dr. Hans-J u rgen E. Hess and Dr. Roger P. llelson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 60, after "or" insert ethyl ester Column 8, line 14, "46.6% should read 45.6%

Signed and sealed this 8th day of October;- 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

